In response to the growing interest in hydric need in eucalypt plantations and plant response as a function of environmental conditions, this work aimed to calculate water consumption in 2-year-old Eucalyptus grandis x Eucalyptus urophylla clones located both on irrigated and non-irrigated plantations. This work is divided into two parts. In the first, stomatal conductance is determined and the effect of seasonal variability of environmental variables is verified. In the second, stomatal resistance is modeled and eucalypt transpiration is calculated by the Penman-Monteith method. The experimental site was located in Belo Oriente, Minas Gerais, at 19º 18'23" S latitude, 42º22'46" W longitude and 220 m altitude. Stomatal conductance was measured in three different periods: humid period, early dry period, and dry period. Average values of stomatal conductance ranged from 0.41to 0.22mol m-2 s-1 for the irrigated treatment and from 0.38 to 0.24 mol m-2 s-1 for the non-irrigated treatment. Stomatal conductance was also found to decrease between the humid and dry periods. This variation was related with some environmental variables and soil moisture.
Stomatal conductance; hydric needs; seasonal variation and eucalypt
